1. Field of the Invention
The present invention relates to an improvement in a fuel supply control system for an engine, comprising a diaphragm attached to a valve housing to define a negative pressure working chamber, a control valve which is connected to the diaphragm and which is operable to be opened and closed by advancing and returning of the diaphragm due to generation and extinction of a negative pressure in the negative pressure working chamber, the control valve being incorporated into a fuel passage system which provides communication between a portion of a fuel tank below a fuel oil surface and a fuel supply section in the engine, the negative pressure working chamber being in communication with a negative pressure generating section in the engine through a negative pressure conduit.
2. Description of the Related Art
Such a fuel supply control system for an engine is already known, as disclosed in, for example, Japanese Utility Model Application Laid-open No. 2-27145.
Especially, a general-purpose engine may be largely inclined or overturned during transportation or storage thereof. In such a case, an engine provided with the conventional fuel supply control system has a possibility that a lubricating oil in the engine may flow out of the negative pressure generating section toward the negative pressure conduit.